大流态混凝土当量粉浆体体积研究

发布时间：2018-07-27 20:04

【摘要】：随着现代建筑物不断向高处发展,大流态混凝土因具备较大的流动性和优异的工作性能而备受青睐,但随着流动度的增加,拌合物离析、稳定性差的风险就不断提高,如何在保持流动度增大的同时大流态混凝土仍具有良好的工作性能已成为重要的研究课题,而为解决该问题而提出的粉体、水粉比等参数又很难得到应用。为此本文提出当量粉浆体体积这一概念,并在此基础上延伸出基于当量粉浆体体积的大流态混凝土配合比设计方法,并通过试验验证这一概念的可行性。主要研究内容有:(1)因大流态混凝土缺少统一、准确的定义,为明确研究对象,本文综合多方资料对大流态混凝土进行定义;对比并指出大流态混凝土配制理论与普通混凝土的差异,为大流态混凝土配合比设计指明了要点与方向;(2)通过需水量比试验测定各粉体的当量系数,提出了胶砂当量粉浆体体积,并在对水泥胶砂进行当量粉浆体体积试验研究发现,胶砂流动度与当量粉浆体体积近似呈线性关系,为大流态混凝土配合比设计提供了思路;(3)融入当量粉浆体体积,提出了大流态混凝土配合比设计方法,通过纯水泥和加入矿物掺料的混凝土试验,确定不同流动度下的大流态混凝土所对应的合理当量粉浆体体积范围;(4)在当量粉浆体体积确定的条件下,通过试验研究粗骨料最大粒径和级配对大流态混凝土工作性能、强度、耐久性的影响。
[Abstract]:With the continuous development of modern buildings, large-flow concrete is favored for its high fluidity and excellent working performance. However, with the increase of fluidity and segregation of the mixture, the risk of poor stability increases continuously. It has become an important research topic that how to keep the flow degree increasing while the large flow concrete still has good working performance, and it is difficult to apply the parameters such as water-powder ratio to solve this problem. In this paper, the concept of equivalent slurry volume is proposed, and the design method of mass flow concrete mixture ratio based on equivalent slurry volume is extended, and the feasibility of the concept is verified by experiments. The main research contents are as follows: (1) due to the lack of a unified and accurate definition of large-flow concrete, this paper defines large-flow concrete by synthesizing multi-party data; Comparing and pointing out the difference between the mixing theory of large flow concrete and ordinary concrete, it points out the key points and direction for the mix proportion design of large flow concrete. (2) the equivalent coefficient of each powder is measured by water demand ratio test. In this paper, the equivalent slurry volume of cement sand is put forward, and the experimental study on the equivalent slurry volume of cement mortar shows that the flowing degree of cement sand is approximately linear with the equivalent slurry volume. It provides a way to design the mix ratio of large flow concrete. (3) put forward the design method of mix proportion of large flow concrete with equivalent slurry volume, and pass the test of pure cement and concrete with mineral admixture. (4) under the condition of the determination of equivalent slurry volume, the working performance and strength of coarse aggregate maximum particle size and gradation matched large-flow concrete are studied through experiments. The effect of durability.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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